Linux for PowerPC. Brought to you by The LinuxPPC Project.
Based on Red Hat Linux release 5.0 (Hurricane)
Kernel 2.2.9 on a PowerPC 750

Before you can boot with any of these methods there are a few things
you will need to take care of first. You will need to set the jumpers
to boot from the Flash that has the PPCbug image on it. It
seems that most boards come from PREP set up to boot VxWorks.
If you connect your serial cable to the board and see any mention of VxWorks,
you need to set the jumper to boot from the other Flash bank.
On the boards that I have recieved from PREP they were all set to boot
from bank A, which was VxWorks. When I switched them
to bank B, I was able to boot with PPCbug. There are two environment parameters
that must be set in NVRAM before you can try to boot Linux. First,
the option 'Network PReP-Boot Mode Enable' must be set to yes.
This sets up the memory model the way that Linux expects it.
Second, the option 'VME3PCI Master Master Enable' enable must be
set to no. I do not know why this needs to be done other than it
will not work if it is set to yes. These environment
parameters can all be set with the env command from the PPCbug prompt.
I have provided a couple of examples of what our environments look like
on boards that boot Linux.

This example comes from an MVME2432 that boots over the network with
tftp. Unlike the examples below it does not need/use bootp
It boots with NFS. It also boots automatically
on power-up or reset. The parameters that allow it to boot
correctly all begin with 'Network Auto Boot'.

This example is from an MVME2603 with a SCSI disk attached
with SCSI id 2. It boots automatically from partition
one on power-up or reset. The parameters that allow it to boot
automatically all begin with 'Auto Boot'

This example comes from an MVME2304 that boots over the network with
bootp and tftp. It can boot with NFS or ramdisk depending on what
kernel it gets via bootp/tftp. It also boots automatically
on power-up or reset. The parameters that allow it to boot
correctly all begin with 'Network Auto Boot'.